Methods, apparatus and systems for measuring snow structure and stability

ABSTRACT

The present inventions relate generally to methods, apparatus and systems for measuring snow stability and structure which may be used to assess avalanche risk. The disclosed apparatus includes a sensing unit configured to sense a temperature of a layer of snow as the sensing unit is being driven into the layer of snow. The disclosed apparatus may also be configured to take other environmental measurements, including resistance to penetration, humidity, grain size, slope aspect and inclination. Methods and apparatus are also disclosed for generating a profile of snow layer temperature according to depth based on the sensed temperature. Systems and apparatus are also disclosed for sharing the generated profiles among a plurality of users via a central server, and for evaluating an avalanche risk at a geographic location.

This application is a Continuation of U.S. patent application Ser. No.14/063,557, entitled METHODS, APPARATUS AND SYSTEMS FOR MEASURING SNOWSTRUCTURE AND STABILITY, filed Oct. 25, 2013, which claims the benefitof priority to U.S. Provisional Application Nos. 61/718,471 filed Oct.25, 2012 and 61/822,284 filed May 10, 2013, all of which are herebyincorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a portable device for assessing thestructure and stability of a layer of snow.

BACKGROUND

Every year, hundreds of people around the world die in avalanchesbecause they lack crucial information about the stability of thesnowpack Annual avalanche fatalities have increased by 220% over thepast two decades, fueled by a rapidly growing interest in backcountrysports, now the fastest growing segment of the snow sports industry.Moreover, avalanche risk is not limited to recreationalists, but affectsthe military, researchers, search and rescue personnel, transportationauthorities, and alpine mining operations alike.

Current approaches to avalanche safety are reactive. Beacons, probes,shovels, and avalanche airbags are all designed to help increase chancesof survival after you've been trapped in an avalanche. With a fatalityrate greater than 50% for those buried in an avalanche, these devicesfail to address the real need—avoiding avalanches altogether. Today'smanual snow pit methods to detect weak layers in the snow under foot arehighly error prone, time-consuming, subjective, and only provideinformation about conditions in one location. There is a significantneed for a low-cost device that can increase the speed and accuracy withwhich snowpack profiles can be evaluated.

SUMMARY OF THE DISCLOSURE

In one aspect, the present disclosure is directed at an apparatus formeasuring snow structure and stability. The apparatus can include a polehaving a length, a first end and a second end; a sensing unit located atthe first end of the pole, the sensing unit including a head shaped forprobing a layer of snow, the sensing unit configured to sense atemperature of the layer of snow; and a range sensor configured tomeasure a distance between the range sensor and a surface of the layerof snow. The apparatus can also include a processor configured todetermine a depth of penetration based on the distance measured by therange sensor and the length of the pole; and determine a profile of snowlayer temperature according to depth based on the temperature sensed bythe sensing unit.

In some embodiments, the apparatus can include an ambient temperaturesensor configured to sense a local ambient temperature.

In some embodiments, the ambient temperature sensor of the apparatus canbe integrated into the sensing unit.

In some embodiments, the apparatus can include a notification deviceconfigured to indicate to a user that a stable temperature measurementhas been taken and to direct the user to insert the sensing unit deeperinto the layer of snow.

In some embodiments, the notification device can include at least one ofa data display screen, a speaker, a light emitting diode (LED), and ahaptic device.

In some embodiments, the apparatus can include a notification deviceconfigured to direct a user to stop inserting the sensing unit deeperinto the layer of snow until a stable temperature measurement can betaken.

In some embodiments, the apparatus can include an optical sensorconfigured to measure a distance of displacement, and wherein theprocessor is configured to determine the depth of penetration based atleast in part on the distance of displacement measured by the opticalsensor.

In some embodiments, the apparatus can include an accelerometer, whereinthe processor is configured to determine the depth of penetration basedat least in part on an acceleration measured by the accelerometer.

In some embodiments, the apparatus can include a data display screen.

In some embodiments, the apparatus can include a wireless communicationdevice configured to automatically determine the geographical positionof the apparatus.

In some embodiments, the apparatus can include a wireless communicationmodule for communicating with at least one of a wireless data networkand a mobile device.

In some embodiments, the range sensor of the apparatus can be configuredto measure distance by transmitting and receiving a beam of radiation.

In some embodiments, the range sensor of the apparatus can be configuredto measure distance using sound waves.

In another aspect, the present disclosure is directed at a method formeasuring snow structure and stability which can include: (a) sensing,at a probe that is being inserted progressively deeper into a snowlayer, a temperature of the snow layer; (b) measuring a depth ofpenetration based on the distance measured by a range sensor; and (c)repeating steps (a)-(b) to determine a profile of snow layer temperatureaccording to depth based on the sensed temperature and the measureddepth of penetration.

In some embodiments, the method of the present disclosure can includedetermining to start a test based on at least one of a sensed resistanceto penetration and input from an optical sensor; and determining to endthe test when the measured depth of penetration decreases or remainsconstant for a predetermined period of time.

In some embodiments, the method of the present disclosure can includeindicating to a user that a stable temperature measurement has beentaken and directing the user to insert the probe deeper into the snowlayer.

In some embodiments, the method of the present disclosure can indicateto the user that the stable temperature has been taken through at leastone of a data display screen, a light-emitting diode (LED), and a hapticindicator.

In some embodiments, the method of the present disclosure can includedirecting a user to stop inserting the probe deeper into the snow layeruntil a stable temperature measurement can be taken.

In some embodiments, the method of the present disclosure can includemeasuring the depth of penetration is based at least in part on adisplacement measured by an optical sensor.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 is a diagram of an example snow-measurement device in itsextended position, according to embodiments of the present disclosure.

FIG. 2A is an illustration of how an example snow-measurement devicemeasures the depth of its tip beneath a snowpack using a range sensor,according to embodiments of the present disclosure.

FIG. 2B is a diagram of the tip of an example snow-measurement deviceincorporating an optional optical flow sensor and optical trigger,according to embodiments of the present disclosure.

FIG. 3A is a diagram depicting a cross-section view of the connectionbetween an example snow-measurement device's handle and pole, accordingto embodiments of the present disclosure.

FIG. 3B is a diagram depicting the segments which comprise an examplesnow-measurement device's pole, according to embodiments of the presentdisclosure.

FIG. 3C is a close-up diagram depicting an example snow-measurementdevice in its collapsed position, according to embodiments of thepresent disclosure.

FIG. 4 is a diagram of the interface between the lower pole segment andthe lower-mid pole segment of an example snow-measurement device,according to embodiments of the present disclosure.

FIG. 5 is a diagram of the locking mechanism incorporated into the topof an example snow-measurement device's pole and handle when the deviceis in its extended position, according to embodiments of the presentdisclosure.

FIG. 6 is a diagram of the locking mechanism incorporated into the topof an example snow-measurement device's pole and handle when the deviceis in its collapsed position, according to embodiments of the presentdisclosure.

FIG. 7 is a diagram of the tip of an example snow-measurement deviceincorporating a force sensor comprising a load cell diaphragm, accordingto embodiments of the present disclosure.

FIG. 8A is a diagram of the tip of an example snow-measurement deviceincorporating a force sensor comprising a load cell cylinder, accordingto embodiments of the present disclosure.

FIG. 8B is a diagram of the tip of an example snow-measurement deviceincorporating a force sensor comprising a pressure cavity and pressuresensor, according to embodiments of the present disclosure.

FIG. 8C is a diagram of the tip of an example snow-measurement deviceincorporating a hall effect sensor, a compression spring, and a magneticupper end, according to embodiments of the present disclosure.

FIG. 9 is a diagram of the tip of an example snow-measurement deviceincorporating a weather o-ring, according to embodiments of the presentdisclosure.

FIG. 10 is a diagram of the tip of an example device incorporating aweather tubing, according to embodiments of the present disclosure.

FIG. 11 is a diagram of the tip of an example snow-measurement deviceincorporating a weather-proof filler, according to embodiments of thepresent disclosure.

FIG. 12A is a side view of the handle of an example snow-measurementdevice and its associated components, according to embodiments of thepresent disclosure.

FIG. 12B is a front view of the handle of an example snow-measurementdevice and its associated components, according to embodiments of thepresent disclosure.

FIG. 12C is an illustration of the difference between slope aspect andslope inclination, according to embodiments of the present disclosure.

FIG. 13 is a block diagram of an example snow-measurement device'selectronic subsystems, according to embodiments of the presentdisclosure.

FIG. 14 is a flow-chart depicting the process for using an examplesnow-measurement device, according to embodiments of the presentdisclosure.

FIG. 15 is a diagram of an example snow-measurement device that uses anexternal mobile-device (e.g., a smartphone) for a screen instead ofincluding a display on the snow-measurement device itself, according toembodiments of the present disclosure.

FIG. 16 is a diagram of an example snow-measurement device that includesa mobile-device mount inside the handle, according to embodiments of thepresent disclosure.

FIG. 17 is a flow-chart depicting the data processing algorithms used byan example snow-measurement device to derive snow stratigraphy from rawpenetration data, according to embodiments of the present disclosure.

FIG. 18 is an illustration of the data flow from an examplesnow-measurement device to an online database and to remotely locatedusers, according to embodiments of the present disclosure.

FIG. 19 is an illustration of a user interface for an examplemobile-device-based application to view data collected by asnow-measurement device, according to embodiments of the presentdisclosure.

DESCRIPTION

The system can introduce a portable handheld snowpack measurement tool(the “snow-measurement device” or “device”) that helps users morequickly and accurately assess snowpack and other avalanche risk factors,helping them make informed travel decisions in avalanche terrain. Thedevice can also be used for purposes unrelated to avalanches, such ashydrology and soil measurement, among others. Additionally, the systemincludes a way of sharing user and geographic specific information withother users via an online database. The physical device measures andsaves snowpack information, which the user can then upload to thedatabase for other users' benefit. In this way, the physical devicecrowd sources safety information across a broad network of users andintegrates and tracks this data over time online. Finally, the systemincludes a data interpretation component, where aggregated data isanalyzed to look for trends between individual data results andlarge-scale avalanche activity and changes in snow structure.

An example of a consumer use scenario for this product would be abackcountry skier who takes periodic measurements with the device whiletraveling up a mountain in avalanche terrain. The measurements sheacquires on her journey up the mountain helps her understand thefeatures of the snowpack, and inform her decision about where she feelsit is safe or unsafe to travel in the terrain. The user is able to shareinformation across device user interfaces, extract valuable data fromexternal sources, and report localized conditions externally. With manydatasets in the database, trends relating snow structure, location,terrain characteristics, avalanche risk, water resources, and weatherpatterns can be uncovered.

An example of a professional use scenario for this product would be amountain guide, avalanche forecaster, ski patroller, or scientist thattakes frequent measurements with the device while in mountain terrain tobetter ensure the safety of their clients/resort, or for scientific andsnow study purposes. With the ability to gather more information inreal-time, view information from across the network, and track thisinformation historically, avalanche professionals can not only be ableto make better terrain management decisions, they can also be able tomake better forecasts. In a similar manner, hydrologists and snowscientists can be able to use this tool to gather stratigraphic andmicro-structural snow data, and ultimately draw better conclusions aboutsnow and water resources around the globe. Additionally, the oil sandsindustry can benefit from this apparatus by being able to quicklyevaluate the hardness of surface oil layers to determine the sands'readiness for collection and further processing.

In one embodiment, the device can be a portable or hand held tool thatallows the user to assess snowpack risks in real time while traveling insnowy terrain.

The device can use a snow penetration resistance sensor and a depthsensor for determining the depth of the snow penetration resistancesensor. The device also can include other subsystems necessary forrecording and displaying how the snowpack's resistance to penetrationvaries with depth. This knowledge can contribute to identifying areaswith avalanche potential.

Combined with additional sensor readings, such as, but not limited to,slope inclination, slope orientation, ambient temperature, temperatureprofile of a snow layer as a function of depth, snow grain size, snowgrain size profile as a function of depth, wind, weather forecast,weather history, user weight, altitude, snow water content, layerenergy, and geolocation, the device can give users a quick, easy-to-readdata output of the snow features with unprecedented accuracy and ease ofuse, thereby improving backcountry information management andpotentially safety.

FIG. 1 is a schematic view of an exemplary device in the extendedposition, according to some aspects of the present disclosure. In someembodiments, the device can include a one-meter or longer collapsiblecylindrical pole 100 with a handle 102 on one end, and a snowpackresistance sensor 104 on the other end. Pole 100 can be made ofaluminum, steel, titanium, carbon fiber, plastic, and/or other materialsthat can be made into tubing. Handle 102 can be made of rubber, metal,and/or plastic, or any other moldable, machinable, or otherwise formablematerial. Other snowpack measurement sensors (i.e. temperature) can alsobe incorporated into a tip 106 (tip 106 refers to the end of the probeand any snowpack measurement sensors located there, and snowpackresistance sensor 104 is said to be part of tip 106). One or moresensors for determining the depth of tip 106 can be incorporated intothe device (e.g., snow depth sensor 108 (see FIG. 2A), optical flowsensor 208 (see FIG. 2B)). Handle 102 serves as a place for the user tograb the device with their hand(s) and push the pole 100 through thesnow to obtain a measurement. Additionally, handle 102 can containembedded electronics, including, but not limited to: user interfacebuttons 110, a display 112, an accelerometer 118, and an electroniccircuit 114 necessary for collecting, processing, displaying, andtransmitting data and snowpack measurements. Finally, a power supply 116is embedded in the handle and provides power to electronic circuit 114and snowpack measurement sensors 104 and snow depth sensor 108, as wellas any other sensors located in the device.

The device can optionally be equipped with a ski pole basket (not shown)at tip 106 to double as a ski or hiking pole. In this case, a cover canslide over tip 106 to prevent it from damage. Additionally, acollapsible extension can be added at tip 106 to increase the overalllength so that the device can be used as an avalanche rescue probe inemergency situations.

FIG. 2A is a schematic illustration of how snow depth sensor 108operates to measure the depth of tip 106, according to some aspects ofthe present disclosure. The depth 200 of tip 106 is measured as theprobe penetrates a snowpack 202. This is done by range-finding snowdepth sensor 108, which calculates the depth 200 (D) of the tip 106 bysubtracting a distance 204 (X) to the snow surface from a pre-determinedprobe length 206 (L). Range-finding snow depth sensor 108 may comprisean infra-red (IR) range-finding device, a radio frequency (RF)range-finding device, or a range-finding device that operates by sendingand receiving sound- or pressure-waves (e.g., an ultrasonic rangesensor).

The pole diameter can be ¾ inches or less so that less force is requiredto push the probe through the snowpack. As device tip 106 enters snowlayers of different hardness, a different amount of force is required topenetrate the different hardness layers. However, the variations inforce required to penetrate the snowpack is reduced by choosing a smalldiameter pole, which can result in a penetration closer to constantspeed. Because penetration resistance is somewhat dependent onpenetration speed, better data can be recorded with a smaller diameterpole where penetration speed is near constant. If penetration resistanceis dependent on speed, a lookup table can be used to adjust measuredresistance based on the speed at which that resistance was measured. Alookup table for speed correction can be used because the speed ofpenetration can be calculated at any given point based on the rate ofchange of the depth 200. The average speed between two depth readingstaken close together can show a speed very close to tip's 106 actualspeed through snowpack 202.

FIG. 2B shows an alternative embodiment, where depth 200 of tip 106 iscalculated using an optical flow sensor 208 (such as those found in anyoptical computer mouse) on tip 106, according to some aspects of thepresent disclosure. Here, optical flow sensor 208 is mounted at tip 106and oriented to look radially outward into snowpack 202. This ispossible because tip 106 slides through snowpack 202, and optical flowsensor 208 can derive displacement based on the changing image it seesas it slides by the snow.

Additionally, an optical trigger 210 can be incorporated into tip 106 todetect the exact moment when tip 106 enters the snowpack 202. If theoptical flow sensor 208 is not incorporated, optical trigger 210 isuseful for providing the device with an absolute reference for thebeginning of the test. Optical trigger 210 may be a photoresistor.

Another embodiment uses both range-finding snow depth sensor 108 andoptical flow sensor 208. This is advantageous over using a single sensorbecause range-finding sensors suitable for snow depth sensor 108 showabsolute depth with some error, and optical flow sensor 208 showsrelative motion with some error. If necessary, more accurate movement ofthe device can be measured by having both an absolute depth sensor (suchas snow depth sensor 108) and a relative motion sensor (such as opticalflow sensor 208). Combining these technologies may also be useful if onesensor has a limited sample rate, because the other sensor can then beused to fill in information between samples taken at a limited rate.

Ultimately, incorporation of the above sensors can provide a depthmeasurement at a time interval dependent on the maximum sample rate ofsaid depth measurement sensors. Infrared and ultrasonic sensorstypically have sampling rates lower than snowpack resistance sensor 104,requiring that depth values between depth measurement sensor readings bedetermined by interpolation. While linear interpolation is a goodapproximation if speed is near constant between depth measurement sensorreadings, better results can be obtained if the interpolationincorporates data from accelerometer 118 to account for speed changesbetween depth measurements. While accelerometer 118 is shown mounted inhandle 102 in FIG. 1, it is to be understood that the accelerometer maybe mounted anywhere in the device, including pole 100 or tip 106.Similarly, optical flow sensor 208 can provide information about thesespeed changes.

FIG. 3A is a schematic cross-section view illustrating how handle 102can connect to the top of cylindrical pole 100, according to someaspects of the present disclosure. Drawn is one half of handle 102.Handle 102 fits around cylindrical sliding tube 300. A flanged stop 302is press fit, glued, or welded into the sliding tube 300, and the flangesits inside a flange groove 303 in handle 102 to prevent sliding tube300 from sliding along its axis inside handle 102. A cylindrical upperpole segment 304 fits inside sliding tube 300 to form a sliding fit. Amulti-conductor tether 306 runs inside a hole through the axis offlanged stop 302. An upper tether collar 308 is fixed onto the tether306 with tether collar set screws 310, preventing tether 306 fromsliding inside upper tether collar 308. Upper tether collar 308 sitsinside a collar groove 309 in handle 102, which anchors both uppertether collar 308 and tether 306 in handle 102.

FIG. 3B is a schematic illustration showing the collapsed device foldedinto approximately one quarter of the full, extended length, accordingto some aspects of the present disclosure. Continuing away from handle102 (see above, FIG. 3A) and towards tip 106, tether 306 runs throughupper pole segment 304, and then through an upper-mid pole segment 311,a lower-mid pole segment 312, and a lower pole segment 314. The tetherterminates at tip 106, where it is electrically connected to anysnowpack measurement sensors in the tip 106, creating an electrical andmechanical connection between handle 102 and tip 106. At interfacesbetween pole segments there is a ferrule 316 and a ferrule cone 318 onone pole segment and a ferrule socket 320 on the other pole segment. Alower tether collar 322 is fixed inside lower pole segment 314 withepoxy, glue, or a weld, or by means of a press fit between the outsidediameter of lower tether collar 322 and the inside diameter of lowerpole segment 314. Lower tether collar 322 is fixed onto tether 306 withtether collar set screws 310, preventing tether 306 from sliding insidelower tether collar 322. Tip 106 is attached to the lower end of lowerpole segment 314 by means of a press fit or threaded connection.

The sliding interface between sliding tube 300 and upper pole segment304 allows the motion necessary to collapse and extend the probe in thefollowing manner. When the device is in the collapsed position as shownin FIG. 3B, the user can place one hand on handle 102, and the other onupper pole segment 304, and slide them away from each other. This motionremoves the slack in tether 306 between pole segments, causing ferrulecone 318 to guide ferrule 316 into ferrule socket 320. When the motionis complete, each ferrule cone 318 and ferrule 316 sits inside theferrule socket 320, forming a connection between pole segments in asimilar manner as many collapsible tent poles and avalanche rescueprobes. When the user wishes to collapse the device, they must simplyslide handle 102 and upper pole segment 304 towards each other, whichreturns the slack in tether 306 between the pole segments, allowing theuser to fold the device at the exposed sections of flexible tether 306.Tether 306 helps contain the collapsed device as a single unit, easingstorage and handling of the collapsed device.

The components shown in FIG. 3A and FIG. 3B can be made of, but notlimited to, plastic, aluminum, steel, stainless steel, and titanium. Inembodiments where pole 100 is electrically conductive, an electricalground can be connected to upper pole segment 304 such that the groundcontinues all the way to tip 106. This helps shield tether 306 fromexternal sources of electrical noise. Additionally, theelectromechanical contacts created when pole 100 is extended can be usedas a switch to turn the device on.

FIG. 3C shows an exemplary embodiment for bundling the device togetherin the collapsed position for ease of transport and storage. An elasticstrap 324 at the bottom of the handle 102 can be wrapped around the polebundle 326 to contain them and keep the entire collapsed unit together.

FIG. 4 is a close-up view of the interface between lower pole segment314 and lower-mid pole segment 312, according to some aspects of thepresent disclosure. Ferrule 316 provides a tether anchor mechanical stop400 for lower tether collar 322. As described above, theglue/weld/press-fit connection between lower tether collar 322 and lowerpole segment 314 prevents the lower tether collar from sliding towardsthe tip due to force transmitted by compression of tether 306, which canbe small compared to force pulling lower tether collar 322 away from thetip due to the tension force in tether 306. Instead of designing theglue/weld/press-fit connection tolerate this large tension force, theglue/weld/press-fit between ferrule 316 and lower pole segment 314 canbe used, where the lower end of the ferrule functions as a tether anchormechanical stop 400. Curved tether interfaces 402 are shown on ferrulecone 318, which help prevent abrasion and wear on the tether at thesesliding and bending interfaces.

FIG. 5 shows a feature for locking the sliding mechanism described aboveso that the device remains extended or collapsed throughout use,according to some aspects of the present disclosure. In someembodiments, a spring plug 506 can be attached inside the upper end ofthe upper pole segment 304 by press-fit, adhesive, or a weld. A springplug flat 508 is a feature on spring plug 506 that accommodates a springarm 504, which is fixed in place by press-fit, adhesive, or a weld. Atthe lower end of the spring arm 504 is a spring button 500, attached byadhesive, nut and bolt, or a weld. This secures the assembly of springplug 506, spring arm 504, spring button 500, and upper pole segment 304such that the center of spring button 500 is located at the center of aspring button hole 502 on upper pole segment 304. The spring arm is heldin place at the interface between spring plug 506 and upper pole segment304. Finally, a locking indent group 510 is a feature in the slidingtube 300 ½ inch or less below the lower face of flanged stop 302.

At the end of the sliding motion to extend the device, sliding tube 300clears the spring button 500 at the end of the sliding motion, allowingspring button 500 to pop through spring button hole 502. This ispossible because spring arm 504 is pre-bent to cause it to exert aradially outward force on spring button 500. The user is then only ableto collapse the device if he pushes the spring button 500 in whilesliding the handle 102 towards upper pole segment 304. Without thislocking mechanism, handle 102 and top pole segment 304 could slidetowards each other while the user pushes the device into the snowpack,resulting in the device's collapse and making data collection difficult.Because of the cold-weather use case of this invention, the springbutton should be large enough to use with gloved hands ( 3/16 inch orgreater diameter).

As mentioned above, to collapse the device, the user pushes in springbutton 500 and then slides handle 102 and upper pole segment 304 towardseach other. Sliding tube 300 then slides over spring button 500, therebydisengaging the locking mechanism. When the collapsing sliding motion iscomplete, locking indent group 510 squeezes the upper part of upper polesegment 304, resulting in enough friction to lock the device in thecollapsed position. This is convenient because it maintains thecollapsed position while the user folds the device at the sections ofexposed tether 306 and transports the device between test locations.

Spring arm 504 can be made of an elastic material such as spring steel,and an exemplary material for spring button 500 is stainless steel.Exemplary materials for the other parts introduced in FIG. 5 are highstrength aluminum or steel, chosen for machinability, strength,corrosion resistance, moderate cost, and high strength to weight ratio.

FIG. 6 is a close-up schematic view of the sliding/locking mechanismwhile collapsed, according to some aspects of the present disclosure.Here, sliding tube 300 covers spring button 500, and locking indentgroup 510 maintains the mechanism's collapsed configuration during userhandling and transport.

The locking spring button mechanism described above is preferred overtraditional spring buttons because it creates enough clearance insideupper pole segment 304 to accommodate tether 306. Additionally, the wayspring arm 504 is anchored at the upper part of upper pole segment 304is an easier assembly process than anchoring spring arm 504 at thelocation of spring button hole 502. The collapsing mechanism describedabove requires three inches or more of sliding motion so that there isenough slack to slip pole segments out of each ferrule 316, and thelength of spring arm 504 can easily be adjusted to meet thisspecification. More traditional spring buttons don't allow thisflexibility in location, or provide enough clearance for tether 306 insuch a small diameter tube.

FIG. 7 shows tip 106 and its associated components, according to someaspects of the present disclosure. Lower pole segment 314 connects to aplastic, rubber, metal, or composite damping connector 700 by press fit,threads, adhesive, or a weld. A snowpack temperature sensor 702 or othersnowpack measurement sensor can be incorporated into the dampingconnector 700. Onto the lower portion of damping connector 700 isconnected a tip pole segment 704, which is connected by press fit,threads, adhesive, or a weld. Tip pole segment 704 connects to a tipconnector 706 by press fit, threads, adhesive, or a weld. Tip connector706 is also a suitable location for temperature sensor 702 or othersnowpack measurement sensors. In the lower portion of tip connector 706is a load cell cavity 728. A load cell diaphragm 708 is fixed inside therim of load cell cavity 728 by press fit, adhesive, or a weld such thatit covers the lower end of load cell cavity 728. Onto one of the facesof load cell diaphragm 708 one or more strain gauges 710 are mounted. Atip sheath 712 fixes over the end of tip connector 706 by press fit,adhesive, threads, or a weld. A tip cone 714 fixes into the other end oftip sheath 712. A tip cylinder 716 can be a cylindrical hole runningthrough the center axis of the tip cone 714. A resistance sensingelement 718 can be a cylindrical shaft that ends in a conical tip 719.Slightly above conical tip 719 the diameter of the resistance sensingelement 718 can be reduced to create an overload bumper 720. Theresistance-sensing element 718 continues as a cylindrical shaft thatslip-fits inside the tip cylinder 716. The upper end of theresistance-sensing element 718 can attach to the load cell diaphragm 708by press fit, weld, adhesive, or threads. They could also be machinedout of the same piece of stock, or 3D printed/laser sintered. Forcesensors can be strain gauge or piezoelectric based force transducers.

When the device is pushed through the snowpack, varying amounts ofresistance from different snow layers apply a force on conical tip 719.This force is transmitted through resistance-sensing element 718 andonto load cell diaphragm 708. This force strains load cell diaphragm708, resulting in elongation or compression of strain gauges 710. Thisstrain causes a change in the electronic signal leaving strain gauges710 that flows through load cell wires 726. Load cell wires 726 travelthrough load cell cavity 728, and then through a tip connector hole 730.They can then emerge into a damping cavity 732 before passing into adamping connector hole 734. Any wires from the snowpack temperaturesensor 702 or other snowpack measurement sensors mounted in the dampingconnector 700 also travel through the damping connector 700 and enterthe inside of lower pole segment 304. Here, all wires associated withtip 106 can connect to tether 306, resulting in an electrical connectionbetween handle 102 and sensors in tip 106.

A cone internal angle 736 of tip cone 714 and a tip internal angle 738of conical tip 719 can be 60 degrees or less to decrease the magnitudeof resistance caused by a given snow layer. This is possible becausepenetration resistance decreases as the internal angle of a conepenetrometer tip decreases. This can make it easier for the user topenetrate the snowpack where hard layers are present, as well asminimize variations in penetration speed caused by the varying hardnessencountered by tip 106. The cone internal angle 736 can be furtherdecreased below 60 degrees to prevent tip cone 714 from compressing thesnow in front of it.

Resistance sensing element 718 and other components between the snow andstrain gauges 710 can be lightweight to minimize inertial forces sensedby the snowpack resistance sensor 104. Minimizing this mass can alsoreduce the resonant frequency of the force sensing system and thereforeallow for a higher sampling rate and snowpack measurement resolution.Because robustness is also important for resistance sensing 718 element,high strength aluminum, titanium, or stainless steel are possiblematerials. The maximum diameter of conical tip 719 affects the minimumlayer thickness that can be measured by the device. If the internalangle of the conical tip 719 is small, or if the maximum diameter of theconical tip 719 is large, the thickness of snow affecting the snowpackresistance sensor increases. Some diameter should be chosen based onminimum desired layer resolution. For avalanche safety uses, the deviceuses a conical tip 719 diameter of 0.3125 inches or less. This diametershould not be completely minimized (below 0.1 inches for instance),because small local variations in the snowpack can be expressed if thediameter is on the order of such variations. In case local variations doaffect test results, the device includes a way of probing several timesin the same location and averaging the results to produce a morerepresentative snow profile.

A tip offset distance 740 can be set to bring conical tip 719 out infront of the lower face of tip cone 714. This design can help the devicemaintain a constant speed through snow layer interfaces. Because conicaltip 714's and pole 100's cross-sectional areas are several times largerthan the cross-sectional area of resistance sensing element 718, themajority of the resistance is provided not by the resistance sensingelement 718, but instead by the overall pole diameter. As a user pushesthe device through the snowpack, changes in resistance due to differentsnow layers can make it difficult for the user to penetrate at constantspeed. For instance, as the device breaks through a hard layer andenters soft snow, acceleration occurs. It may be beneficial to measurethe transition from one layer to the next at a constant speed instead ofwhile accelerating. If the tip offset distance 740 is greater than zero,conical tip 719 can enter the next layer while tip cone 714 is still inthe other layer above it. This allows tip cone 714 to help regulatepenetration speed while conical tip 719 senses ahead of tip cone 714 sothat it can measure layer transitions at near constant speed.

Damping connector 700 is an optional feature that can be incorporated toisolate tip 106 from any vibrations in the other parts of the device.When not incorporated, lower pole segment 314 can connect directly totip connector 706 by press fit, adhesive, threads, or a weld,eliminating the need for damping connector 704. Any snowpack measurementsensors embedded in damping connector 700 could then be embedded in tipconnector 706 instead. Additionally, tip connector 706 can be made ofrubber, composite, plastic, or another material with dampingcharacteristics to help isolate the lower parts of tip 106 fromvibrations in the upper device.

FIG. 8A shows an alternative embodiment for the force sensing mechanismdescribed in FIG. 7. Damping connector 700 is not shown in this figure.Instead of load cell diaphragm 708, a load cell cylinder 800 connects toa cylinder force transmitter 802, which then connects toresistance-sensing element 718. Strain gauges 710 can be mounted on theexterior surface of load cell cylinder 800, or cast inside load cellcylinder 800.

The resistance from the snowpack results in a force on theresistance-sensing element 718, which can act to compress load cellcylinder 800 along an axis parallel to lower pole segment 314 and expandelongate load cell cylinder 800 along an axis perpendicular to lowerpole segment 314. This results in a change in the electronic signalleaving strain gauges 710.

The overload bumper 720 can prevent the resistance-sensing element 718from displacing so much that it damages more delicate parts above it,such as the load cell cylinder 800 or load cell diaphragm 708. Thesedelicate components measure force because of elastic deformation, and ifforce continues into the plastic deformation regime, the device's forcesensing mechanism can break and need replacement. To prevent this fromhappening, tip 106 is designed such that resistance-sensing element 718can receive much more force than would normally damage these parts. Whena certain force is applied to the resistance-sensing element 718,overload bumper 720 contacts tip cone 714 and prevents any furtherdisplacement that could damage components inside tip 106. The exactforce and displacement at which overload bumper 720 engages tip cone 714can be tuned by rotating the resistance-sensing element and changing howfar onto load cell diaphragm/cylinder force transmitter 708/802 itthreads. Doing this changes the zero-load distance between overloadbumper 720 and tip cone 714. Finally, changing the stiffness of loadcell diaphragm 708 or load cell cylinder 800 can determine the force inthe system when overload bumper 720 contacts tip cone 714. Most OEM loadcells experience very little displacement (0.003 inches or less) atmaximum load, requiring that this displacement adjustment be equallysubtle. Such tolerances are expensive and difficult to achieve inmulti-part assemblies like this one. To simplify this matter, load celldiaphragm 708 can be a specific material and geometry such that itexperiences more displacement at maximum load without yielding (i.e. amaterial that yields at higher strain). For instance, a spring steel orplastic diaphragm of the right thickness can result in maximum loaddisplacements of 0.025 inches or more. This can ease the tolerancesrequired to protect tip 106 from overloading, because the zero loaddisplacement can then be on the order of 0.025 inches (or less) insteadof 0.003 inches. Additionally, if resistance sensing element 718 threadsinto the load cell diaphragm/cylinder force transmitter 708/802, simplytwisting it changes the zero-load distance between overload bumper 720and tip cone 714, which allows post-assembly fine-tuning of the force atwhich overload protection engages. Additionally, the threading allowsresistance-sensing element 718 to be completely removed from the device,a convenient feature if the tip needs cleaning, replacement, or othermaintenance.

If additional displacement is needed to achieve overload protection, aspring can be added in series anywhere between where the snow contactsthe conical tip 719 and where the force sensor attaches to themechanical ground of the tip 106 (i.e. the tip connector 706). This cangive the sensor assembly compliance at the expense of reducing itsresonant frequency. A possible embodiment of this concept is shown inFIG. 8A, according to some aspects of the present disclosure, where theresistance sensing element 718 includes a compliant flexure 803. Thisreduces the stiffness of the mechanism that carries snowpack resistanceto the force sensor, therefore resulting in larger displacements for agiven applied force. Compliant flexure 803 could be substituted for acompression spring for the same result.

FIG. 8B shows an alternative embodiment for the snowpack resistancesensor 104, according to some aspects of the present disclosure. Here,resistance sensing element 718 has a blunted upper end 804 that endsinside a pressure cavity 806 between tip cone 714 and tip connector 706.Force from the snow results in an increase in pressure inside pressurecavity 806, and this change in pressure is measured by a pressure sensor808.

Pressure cavity 806 can be filled with anything that exhibits viscous orvisco-elastic behavior such as a polymer, oil, or gel. Polymers and gelshave an advantage over a liquid because they hold their shape, requiringno need for a fluid seal to prevent it from leaking out of the pressurecavity 806. However, liquid has the advantage that it has zero shearmodulus, so the weather-proofing seal described in FIG. 11 (below) canbe used to prevent liquid from leaking A seal can also be created by useof a metal bellows or a sealing diaphragm 809 connected to the end ofthe outside diameter of the resistance sensing element 718 and theinside diameter of the tip cylinder 716 or inside diameter of thepressure cavity 806. This sealing diaphragm should be thin (andtherefore compliant) enough to allow enough displacement to adequatelypressurize pressure cavity 806 from typical snowpack resistancepressures (approximately 0-3 MPa).

FIG. 8C shows another embodiment for snowpack resistance sensor 104,where a hall effect sensor 810 and a compression spring 814 are usedtogether to create a force sensor, according to some aspects of thepresent disclosure. Here, resistance sensing element 718 can have amagnetic upper end 812. Compression spring 814 can be in parallel withthe hall effect sensor 810 (mounted onto tip connector 706) and themagnetic upper end 812. Force from the snowpack can compress compressionspring 814, which reduces sensed displacement 816 (S) between magneticupper end 812 and the hall effect sensor 810. Hall effect sensor 810 canmeasure sensed displacement 816 because the motion of the magnetic upperend 812 changes the magnetic field measured by hall effect sensor 810.Similarly, other displacement sensor in parallel with a spring could beused to create a force sensor. Possible other displacement sensorsinclude a linear variable differential transformer (LVDT), a capacitancesensor, or a position sensitive diode. Additionally, instead of axialcompression spring 814 shown in FIG. 8C, a cantilever or diaphragm canbe used to create a spring between the target (in this case, resistancesensing element 718) and the sensor.

FIG. 9 shows a way of sealing the tip 106 with a weather o-ring 900,according to some aspects of the present disclosure. Weather sealing isimportant because it can prevent water, snow, ice, and other debris fromentering the assembly and adding friction between resistance-sensingelement 718 and tip cylinder 716. The electronics in the tip (i.e.strain gauges 710) should also be protected from contaminants. Weathero-ring 900 sits between overload bumper 720 and the lower surface of tipcone 714. Weather o-ring 900 should not be pre-loaded byresistance-sensing element 718, because this would make any forcessmaller than the pre-load force immeasurable by the device (thepreloading re-directs force away from the force sensor and into tipsheath 712.

FIG. 10 shows an alternative embodiment for weather sealing that uses apiece of tubing (weather tubing 1000) instead of weather o-ring 900,according to some aspects of the present disclosure. Weather tubing 1000rests between overload bumper 720 and lower surface of tip cone 714. Toaccommodate the thickness of weather tubing 1000, grooves 1002 and 1004are cut out of resistance-sensing element 718 and tip cone 714,respectively.

FIG. 11 shows another embodiment for weather sealing tip 106, whereweather sealing is done with a filler 1100 approach, according to someaspects of the present disclosure. Filler 1100 fills the space betweentip cylinder 716 and resistance-sensing element 718. Fixture grooves1102 can be added to the inside of tip cylinder 716 to prevent thefiller from slipping inside tip cylinder 716. Alternatively (or inaddition), internal threads on tip cylinder 716 could be added, as wellas external threads on resistance sensing element 718. Resistancesensing element 718 and filler 1100 do not slide relative to oneanother, but the filler 1100 is able to deform and allow displacement ofresistance sensing element 718 necessary for transmitting force to theload cell above it. Filler 1100 can be a cast polymer, allowing it tofill the void space as a liquid before curing into a soft, deformablesolid. Silicone polymers may be suitable because their properties areless sensitive to temperature changes than many other polymers.

A similar seal can also be created by placing o-rings or annular piecesof a soft rubber between resistance sensing element 718 and tip cylinder716 (as opposed to pouring polymer to incorporate the rubber seal).

FIG. 12A shows handle 102 and its associated components, according tosome aspects of the present disclosure. Inside handle 102 is amicrocontroller 1200, a memory subsystem 1222, a snowpack measurementsubsystem 1224, an environmental measurement subsystem 1202 which mayinclude some or all of the following: a GPS block 1212, inclinometer(not shown), a tilt-compensated compass 1215, ambient temperature sensor(not shown), altimeter (not shown), and humidity sensor (not shown), andan external communication subsystem 1204 containing some or all of thefollowing: USB port (not shown), WiFi module (not shown), and Bluetoothmodule (not shown). Display 112 can be visible on the exterior of handle102. A user interface light emitting diode (UI LED) 1208 is also visibleto the user as she holds the device by a grip 1210 (or alternatively, aUI tone can be audible to the user). Buttons 110 are accessible by theuser when she is holding the grip 1210. Handle 102 also can includepower supply 116, range-finding snow depth sensor 108, sliding tube 300,flanged stop 302, upper tether collar 308, and upper end of the tether306.

Handle 102 serves as a place for the user to hold the device, as well ashousing for the electronics that aren't located in tip 106. A GPS block1212 in handle 102 automatically stores the location of each test. Theuser can link each test to the slope's inclination by holding the deviceparallel to the slope and holding the inclinometer button before thetest start button is pressed. Similarly, the user can face downslope andhold the aspect button to store that aspect with the subsequent test. Ifneither of these measurements are taken before a test, the test cansimply lack aspect and inclination information.

Each of buttons 110 should be large enough to press with a gloved hand,and a watertight gasket can be placed around each button to preventwater and other contaminants from entering handle 110.

Note that UI LED 1208 can be replaced or combined with a UI tone, suchthat the information is conveyed as an auditory signal.

FIG. 12B is a schematic illustration of handle 102 and associated userinterface, according to some aspects of the present disclosure. The userinterface is managed by microcontroller 1200, which communicates to theuser via display 112 and UI LED 1208. The user is then able to navigateuser interface 1214 by pressing buttons 110. Buttons 110 enable the userto start a test, look at prior test results, power the device on/off,and view other information managed by the microcontroller.

Handle 102 can be made of two or more main pieces, and a handle partingline 1216 between them can be seen in FIG. 12B. Each piece comestogether around sliding tube 300 to contain it, and parting line 1216makes assembly possible while ensuring that sliding tube 300 cannotleave the handle once the two handle halves are fixed together withglue, screws, snap-fit, ultra-sonic weld, or other means.

FIG. 12C shows how the incorporation of a tilt-compensated compass 1215can be used to measure slope aspect 1218 (i.e., which direction theslope is facing) and inclination 1220 in the same step, according tosome aspects of the present disclosure. The slope aspect and inclinationcan be collected simultaneously by laying the probe on the snowpackfacing directly uphill and holding a button to initiate data collection,and releasing it when the measurements have been taken. This is possiblebecause the tilt-compensated compass 1215 (see FIG. 12A) can make anaccurate compass reading even when the device is not parallel to theground. In addition to bearing, the tilt-compensated compass 1215records pitch and roll, which can be used to derive inclination.

FIG. 13 is a block diagram of an embodiment of the device's electronics,according to some aspects of the present disclosure. Microcontroller1200 is connected to the user interface 1214, an external communicationssubsystem 1204, a memory subsystem 1222, an environmental measurementsubsystem 1202, and a snowpack measurement subsystem 1224.

Microcontroller 1200 can pull data from memory subsystem 1222 andtransmit it to a mobile device (e.g., a smartphone or tablet), computer,or associated web database via external communications subsystem 1204.This is possible because of WiFi, Bluetooth, and USB port modulesembedded in handle 102. Memory subsystem 1222 can be any digital storagesystem, such as an SD card, micro SD card, hard drive, or other system.

Microcontroller 1200 can also record and show environmental data viauser interface 1214 by reading the outputs of the device's environmentalmeasurement sensors in its snowpack measurements subsystem 1224, whichmay include components such as, but not limited to: a humidity sensor,an altimeter, a GPS block, an ambient temperature sensor, aninclinometer, and tilt-compensated compass. Snowpack measurementssubsystem 1224 may also be responsible for managing the functions ofsnowpack resistance sensor 104, snowpack temperature sensor 702, snowdepth sensor 108, and a snow grain type or grain size sensor (notshown). Unlike the snowpack temperature sensor 702, the ambienttemperature sensor discussed above is configured to measure thetemperature of the local ambient atmosphere and not the temperature ofthe snow layer. However, the functions of the ambient temperature sensormay also be performed by snowpack temperature sensor 702.

FIG. 14 is a flow chart of the steps to use the device, according tosome aspects of the present disclosure. The user can first unfold thedevice 1400 and slide the sliding tube 300 to lock the pole in extendedposition. Holding the power button to power on 1402 the device can bedone before or after unfolding the device. Once powered, the userinterface is used to initiate measurements 1406 via theenvironmental/snowpack measurement subsystem, or to view pastmeasurements 1408 that are stored in the device's memory subsystem. Viathe user interface, users can optionally have the device recordenvironmental measurements 1410 such as, but not limited to, GPSlocation, temperature, relative humidity, inclination, and slope aspect.The user can also push the device tip through the snowpack 1412 torecord snowpack measurements 1414. The microcontroller receives theuser's request through button inputs, and then directs theenvironmental/snowpack measurement subsystem to sample from theirassociated sensors. This data is stored in the device's memorysubsystem. From there, the microcontroller processes the data in step1418 as described by FIG. 17 and presents the processed data to the uservia the display, which is part of the user interface. The user caninterpret the data and press one of the buttons to queue that test to beshared 1420 with another device that connects to the device via itsexternal communication subsystem (it is also possible for the user toset the device to automatically queue every test for upload). The usercan repeat these steps as many times as they wish, and then collapse andpower off the device by holding one of the buttons. Powering off 1422 isdone by holding the power button. The device can be collapsed 1424 bypushing the spring button and sliding the sliding tube into the handle.An automatic power-off can occur if none of the buttons are pressed forone minute (the user can adjust this time setting). Test results may betransmitted to a user's mobile device (e.g., a smartphone or tablet).Test results can include any measurement taken by the device, including,without limitation, a profile of snow hardness as a function of depth, aprofile of snow temperature as a function of depth, a profile of grainsize as a function of depth, local ambient temperature, humidity, slopeaspect, or inclination. A mobile device may include a display screen, amemory, a short-range communication module for sending and receivingdata over a short-range wireless link (e.g., Bluetooth, WiFi, or NFC) orover a wired connection, and a long-range communication moduleconfigured to communicate with a central server via a wireless network.Test results may also be transferred to a user's personal computer,which also may include a display, a memory, a processor, and ashort-range communication device. Once the user establishes a wirelessor wired connection in step 1426 with their mobile device or computer,any test queued to transfer can automatically be shared with connecteddevices in step 1428 and can then be viewed on the external device instep 1430 (even if the connection is subsequently broken). Next, anyshared data can then be uploaded to an online database in step 1432 forfurther data analysis, mapping, and interpretation. The exact remainingsteps to transfer information to the database (and the database'sfeatures) are described in a later section.

In addition to the steps outlined above, the user has the option tomeasure the snowpack temperature profile in a separate or concurrentstep. While a fast-acting snowpack temperature sensor 702 could beincorporated into tip 106 such that the temperature profile is recordedat the same time as the hardness profile, an embodiment of the devicecan measure temperature in a different step. The user holds one ofbuttons 110 to enter snowpack temperature measurement mode, and display106 can direct them to put tip 106 just beneath the snowpack surface204. When the slow-acting snowpack temperature sensor 702 has acquired atemperature measurement, the device may direct the user to slowlypenetrate several centimeters using any of an indicator on display 106,an audible tone from a speaker integrated into the device, a sequence offlashes from UI LED 1208, a haptic device configured to vibrate thehandle 102, or any other notifications means known in the art. Once theuser has reached new depth 200, display 106, an audible tone from thespeaker, a sequence of flashes from UI LED 1208, a vibration from thehaptic device and/or some other notification means can signal the userto stop until a stable temperature measurement has been taken. Thisprocess can repeat until the user has pushed the pole 100 as far aspossible through the snowpack. The temperature profile can then begraphed on the display 106 and interpreted by the user.

In addition to the steps outlined above, the user has the option tomeasure the snow grain size of the layers of the snowpack in a separateor concurrent step. A small camera and light source can be incorporatedinto the tip 106 that records images of the snow surface as the devicepenetrates the snowpack. The user can then view these images, along withthe depth at which they were taken to see how the snow grains changethroughout the snowpack. Another possible way of determining grain sizeis to use information from the snowpack resistance sensor, where anadequately high sample rate (at least 5 samples per mm) will showchanges in the snowpack's resistance to penetration resulting from theloading and rupture of individual bonds between snow grains (Schneebeli,M., C. Pielmeier, and J. Johnson. “Measuring Snow Microstructure andHardness Using a High Resolution Penetrometer.” Cold Regions Science andTechnology. 30.1-3 (1999): 101-114.).

FIG. 15 shows an embodiment where an external mobile device (e.g., asmartphone) 1502 can be used for the screen instead of including display106 on the device itself, according to some aspects of the presentdisclosure. The mobile device 1502 may be similar to the mobile devicedescribed above in relation to FIG. 14. Handle 102 still contains amicrocontroller based data acquisition, signal processing, and externalcommunications subsystem 1204, and external communications modules suchas Bluetooth or WiFi modules 1504 are used to send mobile device 1502information to be displayed. The user is able to control the informationon a mobile device display 1506 by pressing buttons 110 on the handle,or buttons integrated into the mobile device application 1508.

FIG. 16 shows an alternative embodiment with a mobile-device mountlocated inside handle 102, according to some aspects of the presentdisclosure. A mobile device housing 1600 covers the mobile device with amobile device-viewing window 1608, and provides a mobile device clamp1604 to hold mobile device 1502 in place. The microcontroller based dataacquisition, signal processing, and external communications subsystem1204 can wirelessly communicate with mobile device 1502, or connectdirectly via mobile device connector 1602. Mobile device-viewing window1608 opens at window hinge 1606, allowing the user to place her mobiledevice 1502 in mobile device housing 1600. The user can operate thedevice and navigate the mobile device user interface by pressing buttons110 on handle 102. UI LED 1208 can provide a way of notifying the userof a test in progress (and other states of the device) that doesn'trequire looking at mobile device display 1506.

These two embodiments that use a mobile device 1502 reduce the cost andsize of the device. Mobile device 1502 can also be charged via themobile device connector 1602.

FIG. 17 is an overview of data processing algorithm used to show snowstratigraphy from raw penetration resistance data, according to someaspects of the present disclosure. A version of the raw test data 1700can be saved to the device's memory subsystem 1222. The raw data can beplotted to display 112 as penetration resistance vs. time as shown by1701 in FIG. 17. To derive penetration resistance with respect to depthrather than time from the raw test data 1700, the first step can be forthe microcontroller 1200 to process and filter 1702 the data withaveraging, median filters, and exponential smoothing. Next, themicrocontroller 1200 can identify the test start 1704 by the test starttrigger from the snowpack resistance sensor 104. If either opticaltrigger 210 or optical flow sensor 208 are present on the device, theycan also be used to detect the exact moment when the device penetratesthe snowpack, and so identify the test start 1704. All data pointscollected before the test start 1704 can be discarded so that the startcoincides with a depth equal to zero. Next, the depth rate of change1706 can be calculated by looking at the relative change between eachsuccessive depth reading. The test end 1708 can be identified because itcoincides with the last collected data point that shows depth was stillincreasing. Alternatively, the test end 1708 can be identified if therate of change between each successive depth reading is below a certainthreshold for a predetermined period of time, i.e., the device hasstopped moving. From here, any data points where the depth rate ofchange 1706 shows that the tip 106 was moving out of the snowpack andnot deeper than the previous point can be discarded 1708. At this point,the data can be saved as a new version.

Considering the sampling rate and depth rate of change 1706 allows forthe calculation of average penetration speed between depth measurements.This calculated penetration speed can be used to correct eachpenetration resistance value for penetration resistance's dependence onpenetration speed by using a lookup table developed experimentally. Thisversion of speed-corrected snowpack penetration resistance vs. depth1712 can be saved to the memory subsystem 1222, and plotted to thedisplay 112 as trimmed and calibrated data 1713.

Next, the speed-corrected snowpack data 1712 can be filtered for easiervisual interpretation. In order to display snowpack penetrationresistance vs. depth data in a way widely accepted by the avalanchesafety community, steps can be taken to show more discrete layers thanseen in the trimmed and calibrated data 1713. Penetration resistancevalues that are within approximately 10% of each other can be averagedto filter out the subtle, yet unimportant variations detected by thesnowpack resistance sensor 104 (averaging shown as step 1714 in FIG.17). Any large change in snowpack resistance can be greater than this10% window, and hence significant hardness transitions can be preserved.After this averaging is complete, the resistance values can be comparedto the standard hand-hardness values accepted by the avalanche safetycommunity by use of a lookup table (shown as step 1716 in FIG. 17). Thelookup table can be generated by experimentally collecting penetrationresistance and hand-hardness data side by side. Finally, areas where thehardness decreases beyond a predetermined percentage (e.g., 50%) withina predetermined range (e.g., 10 cm) can be tagged as an area of concern1720 (i.e., indicative of high avalanche risk). Users can have theoption to adjust these parameters, including both the predeterminedpercentage and the predetermined range, based on their preferences. Thesmoothed data can then be plotted to the display 112 as shown in 1719.The trimmed and calibrated data 1713 and smoothed data 1719 can besuperimposed and displayed simultaneously if desired. Smoothed data 1719therefore constitutes a profile of snow hardness as a function of depth.

In addition to the data processing outlined above, a correlationanalysis can be done to show how closely a given test resembles one ofthe 10 snow hardness (resistance) profiles developed by Schweizer andLütschg in Switzerland (Schweizer, J. and M. Lütschg. 2000. Measurementsof human-triggered avalanches from the Swiss Alps. ProceedingsInternational, Snow Science Workshop, Big Sky, Mont., U.S.A., 2-6 Oct.2000). This can help the user understand the snow packs he measures,because comparison to these well understood ten profiles allows the userto benefit from the extensive studies performed by Schweizer andLütschg. As new snow profile data is collected, these ten profiles canbe re-developed, and new profiles can be added to this correlation test.

While the data processing steps discussed above with regard to FIG. 17relate to measuring snow stratigraphy, they can also be applied tomeasuring a profile of snow layer temperature according to depth, andsnow grain size according to depth. For example, the start of testsdirected at measuring a profile of temperature and depth may betriggered by resistance sensed by snowpack resistance sensor 104,optical trigger 210 or optical flow sensor 208. Similarly, the end ofsuch tests may also be identified as coinciding with the last collecteddata point that shows depth still increasing. Raw temperature and grainsize data can also be smoothed, filtered and averaged in the mannerdescribed above, as well as compared with experimental values asdescribed above. Finally, areas in the temperature and grain size dataindicative of an increased avalanche risk can be tagged as an area ofconcern, potentially using the same or similar algorithms as describedabove.

In addition to the hardware device, this disclosure relates to a uniquedata sharing system to further enhance backcountry safety and avalancheforecasting. Each time measurements are taken with the hardware device,the data is recorded both on the device and automatically shared viaBluetooth and WiFi to a mobile-device application (or other electroniccommunication device). Data includes a snow profile, slope inclination,slope orientation, time, GPS coordinates, temperature gradient, andmore. The device and mobile device application also pull in externaldata on local weather, recent snowfall, etc. Additional computersoftware allows users to view data and move data to and from thehardware device.

Data transported to the mobile device application or computer softwarefrom the hardware device is stored on a server where it can be accessedremotely by a computer or other mobile device devices. Subscribers tothe data services can be able to see all of the data acquired from usersof the hardware device in real-time and historically. Sharing this dataacross a broad network has the potential to create one of the largestsets of information on critical avalanche risk metrics in the world.With an innovative mobile device application and web portal that allowusers to access local, regional, and global data, this information canimprove decision making of individual backcountry adventurers as well asforecasting methods of ski resorts, mines, avalanche forecast centers,guides, and other snow professionals.

Another benefit of a shared data network is that users can be able toview snowpack and other local measurement from other users in theirvicinity or far away, further informing their decisions through thebackcountry. For example, one user planning to go to a certainbackcountry area may notice multiple measurements from other users inthe same location earlier that day. If the measurements convey dangerousinformation, this individual may be able to decide not to go withoutever even setting foot on the slope.

Furthermore, geolocation data integration with mobile mapping and GIStechnologies can allow aggregation of historic avalanche data to formcold and hot zones of avalanche activity—this can be viewed at any time,not only by individual users but also for scientific and weatherresearch purposes among others. The data can be mapped in one, two, orthree dimensions and can even help professionals identify weak areaswithin the snowpack which may be more effectively targeted byexplosives, thereby improving avalanche control precision and reducingcosts.

Lastly, for professionals and more advanced recreational users, asoftware package can allow users to download data from the device totheir computer where they are able to do more complex snow scienceanalytics.

FIG. 18 shows the information flow for how the system sources data fromthe hardware device 1800 for the online database, according to someaspects of the present disclosure. Once the user 1802 has transferredtest results from device 1800 to their mobile device 1502 as describedin steps 1426 and 1428 of FIG. 14, mobile device 1502 can send testresults to server 1804 via a wireless network transceiver 1806. Asdiscussed above, test results can include any measurement taken by thedevice 1800, including, without limitation, a profile of snow hardnessas a function of depth, a profile of snow temperature as a function ofdepth, a profile of grain size as a function of depth, local ambienttemperature, humidity, slope aspect, or inclination. Server 1804, whichmay include at least a processor, an internal memory, and at least oneinterface for receiving and transmitting data, functions as a host forthe data collected by the hardware device 1800 by storing the collecteddata in the internal memory for later retrieval. Server 1804 also canreceive and record information regarding the source of the collecteddata, including a unique identifier corresponding to the source device1800, a unique identifier corresponding to user 1802, the date and timethe data was collected by device 1800, the date and time the data wasreceived by the server 1804, and the geographical location correspondingto the collected data (i.e., where the test results were taken).

Server 1804 may receive similar test results and information frommultiple users, perhaps simultaneously. Furthermore, server 1804 mayalso analyze information from a single user or from multiple users todraw inferences and conclusions about the degree of avalanche risk in acertain area. For example, if server 1804 detects that an anomalouslylarge number of test results from in and around a specific geographicarea indicate a high avalanche risk, server 1804 may determine that thatspecific geographic area poses a high avalanche risk. Server 1804 mayalso determine that a high avalanche risk exists for a geographic areafor which it has not received any data by extrapolating from datareceived regarding neighboring geographic areas. Sever 1804 may also beconfigured to receive information from other information sources, suchas weather-related information (e.g., temperature, humidity and/orwind-speed information) or alerts (e.g., snowfall warnings) from weatherstations or sensors, and to factor in such information when determiningthe degree of avalanche risk for a specific geographic area. If server1804 determines that a specific geographic area poses a high avalancherisk, server 1804 may be configured to proactively send an alert to, forexample, users' mobile devices, weather forecasting centers, avalancheforecasting centers, ski resorts, alpine mines, departments oftransportation, and other recipients. Alternatively, if server 1804receives a safety warning published by avalanche forecasting centers orother information outlets, the server 1804 may forward the safetywarning to all of the recipients listed above.

Other consumers can pull in data from the server 1804 via, for example,a mobile device 1502, which effectively allows users to share their datawith others. Furthermore, avalanche forecasting centers 1808, skiresorts 1810, and other recipients (such as alpine mines, departments oftransportation, etc.) can pull in the data stored on the server 1804.

FIG. 19 shows an example user interface for a mobile-device-basedapplication to view data collected by the device, according to someaspects of the present disclosure. The mobile-device-based applicationin this example may be capable of receiving test results directly from auser's snow-measurement device over a short-range communication linksuch as Bluetooth, WiFi or NFC, as described above. Themobile-device-based application in this example may also be capable ofreceiving test results from server 1804 over a wireless network, andsending test results to server 1804 over the wireless network. An areamap 1900 is visible on the mobile device screen with markers 1902indicating locations where device measurements have been taken. Markers1902 may correspond to device measurements taken by the user's owndevice or to measurements taken by other user's which have beendownloaded from server 1804. Users can press the filter button 1904 tofilter the displayed results based on their associated metadata, such asuser type (recreationalist vs. professional), time of measurement,altitude of measurement, and other parameters. Users also can be able tomove the zoom slider 1906 to zoom in and out of the map, or press the mylocation button 1910 to jump to their current location. Sliding the mapon a touch screen can also scroll to change the visible area. Quickaccess buttons 1908 shown at the bottom of FIG. 19 can be pressed toquickly view additional information accessible via the application, suchas data collected by the currently logged-on user, most recent tests, orsafety warnings published by avalanche forecast centers or otherinformation outlets. Other interfaces can exist to show data in listform, and markers can be clicked on to show detailed snowpackinformation represented in ways as described by FIG. 17. A similarinterface can also be accessed via a web application or tablet.

The subject matter described herein can be implemented in digitalelectronic circuitry, or in computer software, firmware, or hardware,including the structural means disclosed in this specification andstructural equivalents thereof, or in combinations of them. The subjectmatter described herein can be implemented as one or more computerprogram products, such as one or more computer programs tangiblyembodied in an information carrier (e.g., in a machine readable storagedevice), or embodied in a propagated signal, for execution by, or tocontrol the operation of, data processing apparatus (e.g., aprogrammable processor, a computer, or multiple computers). A computerprogram (also known as a program, software, software application, orcode) can be written in any form of programming language, includingcompiled or interpreted languages, and it can be deployed in any form,including as a stand-alone program or as a module, component,subroutine, or other unit suitable for use in a computing environment. Acomputer program does not necessarily correspond to a file. A programcan be stored in a portion of a file that holds other programs or data,in a single file dedicated to the program in question, or in multiplecoordinated files (e.g., files that store one or more modules, subprograms, or portions of code). A computer program can be deployed to beexecuted on one computer or on multiple computers at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

The processes and logic flows described in this specification, includingthe method steps of the subject matter described herein, can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions of the subject matter describedherein by operating on input data and generating output. The processesand logic flows can also be performed by, and apparatus of the subjectmatter described herein can be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processor of any kind of digital computer. Generally, aprocessor can receive instructions and data from a read only memory or arandom access memory or both. The essential elements of a computer are aprocessor for executing instructions and one or more memory devices forstoring instructions and data. Generally, a computer can also include,or be operatively coupled to receive data from or transfer data to, orboth, one or more mass storage devices for storing data, e.g., magnetic,magneto optical disks, or optical disks. Information carriers suitablefor embodying computer program instructions and data include all formsof nonvolatile memory, including by way of example semiconductor memorydevices, (e.g., EPROM, EEPROM, and flash memory devices); magneticdisks, (e.g., internal hard disks or removable disks); magneto opticaldisks; and optical disks (e.g., CD and DVD disks). The processor and thememory can be supplemented by, or incorporated in, special purpose logiccircuitry.

To provide for interaction with a user, the subject matter describedherein can be implemented on a computer having a display device, e.g., aCRT (cathode ray tube) or LCD (liquid crystal display) monitor, fordisplaying information to the user and a keyboard and a pointing device,(e.g., a mouse or a trackball), by which the user can provide input tothe computer. Other kinds of devices can be used to provide forinteraction with a user as well. For example, feedback provided to theuser can be any form of sensory feedback, (e.g., visual feedback,auditory feedback, or tactile feedback), and input from the user can bereceived in any form, including acoustic, speech, or tactile input.

The subject matter described herein can be implemented in a computingsystem that includes a back end component (e.g., a data server), amiddleware component (e.g., an application server), or a front endcomponent (e.g., a client computer having a graphical user interface ora web browser through which a user can interact with an implementationof the subject matter described herein), or any combination of such backend, middleware, and front end components. The components of the systemcan be interconnected by any form or medium of digital datacommunication, e.g., a communication network. Examples of communicationnetworks include a local area network (“LAN”) and a wide area network(“WAN”), e.g., the Internet.

It is to be understood that the disclosed subject matter is not limitedin its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The disclosed subject matter is capable ofother embodiments and of being practiced and carried out in variousways. Also, it is to be understood that the phraseology and terminologyemployed herein are for the purpose of description and should not beregarded as limiting.

As such, those skilled in the art will appreciate that the conception,upon which this disclosure is based, may readily be utilized as a basisfor the designing of other structures, methods, and systems for carryingout the several purposes of the disclosed subject matter. It isimportant, therefore, that the claims be regarded as including suchequivalent constructions insofar as they do not depart from the spiritand scope of the disclosed subject matter.

Although the disclosed subject matter has been described and illustratedin the foregoing exemplary embodiments, it is understood that thepresent disclosure has been made only by way of example, and thatnumerous changes in the details of implementation of the disclosedsubject matter may be made without departing from the spirit and scopeof the disclosed subject matter, which is limited only by the claimswhich follow.

The invention claimed is:
 1. An apparatus for measuring snow structure and stability comprising: a sensing unit for probing a layer of snow, the sensing unit configured to sense a resistance to penetration; an optical flow sensor disposed in the sensing unit and configured to capture a series of images as the optical flow sensor is inserted progressively deeper into the layer of snow; and a processor configured to determine a depth of penetration based on the series of images captured by the optical flow sensor; and determine a profile of penetration resistance according to depth based on the resistance to penetration sensed by the sensing unit.
 2. The apparatus of claim 1, wherein the sensing unit comprises a tip having an inner wall defining a tip cylinder, a resistance sensing element disposed within the tip cylinder, and a weather-sealing filler which fills a space between the resistance sensing element and the inner wall.
 3. The apparatus of claim 1, further comprising a pole having a length, a first end, and a second end, wherein the sensing unit is disposed at the first end of the pole.
 4. The apparatus of claim 3, comprising a range sensor disposed proximate the second end of the pole configured to measure a distance between the range sensor and a surface of the layer of snow, wherein the processor is configured to determine the depth of penetration based at least in part on the distance measured by the range sensor.
 5. The apparatus of claim 4, wherein the range sensor is configured to measure distance using sound waves.
 6. The apparatus of claim 4, wherein the range sensor is configured to measure distance by transmitting and receiving a beam of radiation.
 7. The apparatus of claim 1, wherein the sensing unit comprises a strain sensor comprising at least one of a strain gauge and a piezoelectric based force transducer.
 8. The apparatus of claim 7, wherein the sensing unit comprises a resistance sensing element positioned adjacent to a diaphragm on which the strain sensor is arranged, wherein the diaphragm is configured to distort when the resistance sensing element encounters resistance, and wherein the strain sensor is configured to measure the distortion of the diaphragm.
 9. The apparatus of claim 1, wherein the sensing unit comprises a resistance sensing element positioned adjacent to a pressure cavity filled with at least one of a liquid, an elastomer, and a gel, and a pressure sensor configured to measure a change in pressure in the pressure cavity when the resistance sensing element encounters resistance.
 10. The apparatus of claim 1, wherein the sensing unit comprises a magnetic member that is configured to displace when the sensing unit encounters resistance, and a magnetic field sensor that is configured to measure the displacement.
 11. The apparatus of claim 1, comprising an accelerometer, wherein the processor is configured to determine the depth of penetration based at least in part on an acceleration measured by the accelerometer.
 12. The apparatus of claim 1, wherein the sensing unit comprises an overload bumper which prevents damage to the sensing unit.
 13. The apparatus of claim 1, comprising a data display screen operably connected to the processor.
 14. The apparatus of claim 1, comprising a wireless communication device operably connected to the processor and configured to automatically determine the geographical position of the apparatus.
 15. The apparatus of claim 1, comprising a wireless communication module operably connected to the processor for communicating with at least one of a wireless data network and a mobile device.
 16. A method for measuring snow structure and stability comprising: (a) sensing, at a probe while being inserted progressively deeper into a snow layer, a resistance to penetration; (b) capturing, using an optical flow sensor disposed in the probe, a series of images as the optical flow sensor is being inserted progressively deeper into the snow layer; (c) determining a depth of penetration based on the series of images captured by the optical flow sensor; and (d) repeating steps (a)-(c) to determine a profile of penetration resistance according to depth based on the sensed resistance to penetration and the determined depth of penetration.
 17. The method of claim 16, comprising: determining to start a test based on at least one of a sensed resistance to penetration and input from the optical flow sensor; and determining to end the test when the measured depth of penetration decreases or remains constant for a predetermined period of time.
 18. The method of claim 16, comprising averaging the sensed resistance values within a predetermined threshold of each other.
 19. The method of claim 16, comprising identifying, in a computer processor, areas in the profile of penetration resistance according to depth in which the sensed resistance drops by a predetermined percentage within a predetermined depth as an area indicative of a high avalanche risk.
 20. The method of claim 16, comprising: calculating a penetration speed; and adjusting the sensed resistance to penetration based on the calculated penetration speed.
 21. The apparatus of claim 2, wherein the weather-sealing filler is configured to deform to allow the resistance sensing element to displace, and wherein the inner wall includes fixture grooves to prevent the weather-sealing filler from slipping inside the tip cylinder. 